Key for combination locks



, Sept. 20,1 192?.

E. FRISCHMUTH KEY FOR COMBINATION LOCKS Original Filed May 4. 1925 [12 van for Paenied'se t. 20, 1927.

UNITED STATES.

1,642,725 PATENT OFFICE.

ERNST FBISOHMUTH, OF SIEMENSSTADT, NEAR BERLIN, GERMANY.

. KEY FOB- COMBINATION LOCKS.

Original application filed May 4, 1923, Serial No. 636,605. Divided and this application flied December 10, 1924. Serial No. 755,087.

invention re'lates to improvements in keys for combination locks. This type of locks is locked by pins passing from the stationary part of the lock into the'rotat able part. These pins are transversely divided and are adapted to be longitudinally displaced bv the keyagainst the reslstance of springs in such a manner that their joints coincide with the joint between the parts of in the lock would be forced back too little or too much that not all the joints in the pins would coincide with the omt between the parts of the lock and the cylinder or the drum would not be turned. If, however, an

' trated in the drawing aflixed to this unauthorized person had an opportumty to handle the key, he would be able to measure the length of the pins and to copy the k e for his own use to open the lock 1n thievis intention. 1 v

The object of my invention is to provide a key which ma be so adjusted by simply turning a nut t at it becomes at once useless for opening the lock. The owner need therefore only turn the nut after usmg the key. An unauthorized person 1s then no longer able to open the lock with the key and a copy of it is equally useless I An embodiment of my invention is illus speci- In the I fication and forming part thereof.

drawing represents: g

Fig. 1 a sectionalelevation Fig. 2 an elevation at right angles to Fig. 1

ig. 3 a'plan and I Fig. 4 a detail. Similar parts are indicated by the same numerals of reference throughout-all the figures of the drawin ends provided with springs against a. cam orsteel plate Referring to the%igs 1, 2 and 3 it be noted that the shaft .12 of the improved key. is furnished at its' front end w1th a short bit 13 and with a cylinder 14 provided with bores for the operatin pins 15.: Upon the rear portion of the sha a micrometer screw thread'16 is provided and upon this screw is mounted the ke ring 17, which is secured against rotation '21. fixing pm 18. ,The operating pmsof t e853 h 19 and are forced are at their lower of uneven surface 21. The cam plate 21 is housed in a short sleeve 22. Behind it a nut 23 rides upon the screw thread 16. The plate 21 and the sleeve are connected with the nut 23 by a pin 24, so that they are obliged to take part in its rotation. The cylinder14 and the sleeve 22 are provided with divisions upon their circumference by means of which the correct position of the pins for operating the lock can be adjusted. In this correct position the nut 23 may be locked by a counter nut28.

If itis desired to render the key useless for an unauthorized person, the nuts 24 and 4 23 are turned in one or the other, direction. Owing to the uneven or cam surface of the late 21 the pins 15 are then uneuallyadusted so that the key can no onger be used for unlocking the look;

If it is desired in such keys to interchange the lockingl pins in t e lock, the pins are preferabl made of a special construction as the lengt of the pins must be changed with regard to the face cam 21. A pin which easily admits s own inFi 4. Itconofsuch a change is pins-15 together with the control p sists of a topped part 25 into w ich a screw 26 with a transverse hole through the head is screwed. By screwing the screw 26 more or less into the part 25 the length of the pin may be reduced or increased. In order to lock the screw 26 in the part 25 the latter may be split at the screw-threaded end,

Preferably grooves 27 are cut into the part 25, 4

which increase the difliculty in opemng the look by probing. It will be un erstood that I do not limit myself .to the exact details of construction shown in the drawing as these may obviously be modified in many ways without departin from the spirit'of my invention or sacri cing any of its advantages.

What lclaim' as m invention 1s 1; A key for a com ination lock comprising in combination a shaft, a cylinder having bores being an inte part of said shaft, headed.- pins' in sai moved longitudinally to projected or retracted position, 8 rings in said cylinder bores tending to orce the heads ofsaidpins to retractedposition and a rotatably movable cam'plate for-controlling the movement of said ins.

2. A key or acombination lock comprising in combination a shaft, 0, cylinder bores adapted to be with bores mounted on said shaft, headed ins inc said'bores,ssprings in said cylinder ores tending to force the heads of said ins real-wards, an abutment plate against w ich the heads of the pins are adapted to be forced by said springs and a nut connected with said plate r ding upon a screw-threaded portion of the key shank adapted to move said plate and to adjust said operating pins and means for facilitating their exact 31djustment.

3. A key for a combination lock comprising in combination a shaft, a cylinder with bores mounted on said shaft, headed pins in said bores, springs in said cylinder tending to forcethe heads of said plns rearwards, a face cam against which the heads of the pins are adapted to be forced by said springs and a nut connected with said face cam riding upOna-scre -threaded ortion ment.

Intestimony whereof I aflix my signature.

' ERNST FRISOHMUTH. 

